The prior art door guard (as shown in FIGS. 1 and 2) available in the market includes two types each having a male member and a female member. FIG. 1 shows a first type which includes a thick headed male member 11 perpendicularly fixed to a back of a door 50 and a grip headed female member 10 which has a pair of elastic clip-on arms with a pair of small wheels 101 and 102 at their forward ends for smoothly receiving the thick head of the male member 11 as it enters into the grip head and then is gripped therein. The female member 10 is perpendicularly secured to a nearby wall 60 and keeps in alignment with the female member 10. So that when the door 50 opens to a maximum span, it is retained by the door guard without breaking away except that the door 50 is turned to a closed position again. FIG. 2 shows a second type of door guard which includes a ball headed male member 12 with magnet therein and a metallic female member 13 with a hemispherical depression in a forward end engageable to ball head 121 so as to be attracted by the female member 12. Since the first type is more reliable than the second type, the former is more popular than the latter in architectural design.
However, both of them have the same disadvantages set forth as follows:
a) it is difficult to align a male member with a female member when installing a door guard of the above types and takes time to make sure where is the position on the door back suitable to fix the male or female member. Besides, a poor alignment of the male member with the female member may cause a poor engagement between the members and hence damage the door guard. PA1 b) when the small wheels 101 and 102 of the female member 10 are worn and fatigued, the clip-on arms will lose their gripping function after repeated operations.